This invention relates generally to timer valves and particularly to a hydraulically operated adjustable timer used with a magnetically operated valve for controlling water flow to a chemical block to dissolve and dispense a predetermined amount of chemical.
Electrical and mechanical clockwork timers are well known. The former suffer from the disadvantage of requiring an electrical power supply, the latter from the disadvantage of having to be wound up. Neither type is therefore ideally suited for use with a water supply which is derived from a faucet. Valves are also known to control the closing rate of the valve following delivery of a predetermined quantity of liquid. For example, U.S. Pat. No. 3,376,013, which utilizes a dashpot.
Magnetically operated valves are also well-known which rely on permanent magnets to move a valve element. For example, U.S. Pat. No. 3,212,751 discloses the use of a permanent magnet to pull open a valve, which is then closed by spring action.
The present invention provides a valve which has distinct advantages over known timer and magnetic valves.